NEW YORK, July 3 (Reuters) - Syrian intelligence agenciesare running torture centers across the country where detaineesare beaten with batons and cables, burned with acid, sexuallyassaulted, and their fingernails torn out, Human Rights Watchsaid in a report released on Tuesday.

The New York-based rights group identified 27 detentioncenters that it says intelligence agencies have been using sincePresident Bashar al-Assad's government began a crackdown inMarch 2011 on pro-democracy protesters trying to oust him.

Human Rights Watch conducted more than 200 interviews withpeople who said they were tortured, including a 31-year-old manwho was detained in the Idlib area in June and made to undress.

"Then they started squeezing my fingers with pliers. Theyput staples in my fingers, chest and ears. I was only allowed totake them out if I spoke. The staples in the ears were the mostpainful," the man told Human Rights Watch.

"They used two wires hooked up to a car battery to give meelectric shocks. They used electric stun-guns on my genitalstwice. I thought I would never see my family again. Theytortured me like this three times over three days," he said.

The report found that tens of thousands of people had beendetained by the Department of Military Intelligence, thePolitical Security Directorate, the General IntelligenceDirectorate, and the Air Force Intelligence Directorate.

Human Rights Watch documented more than 20 torture methodsthat "clearly point to a state policy of torture andill-treatment and therefore constitute a crime againsthumanity."

The group called for the U.N. Security Council to refer theissue of Syria to the International Criminal Court (ICC) and toadopt targeted sanctions against officials carrying out abuse.

"The reach and inhumanity of this network of torture centersare truly horrific," Ole Solvang, emergencies researcher atHuman Rights Watch said. "Russia should not be holding itsprotective hand over the people who are responsible for this."

Russia - an ally of Syria - and China have already vetoedtwo council resolutions that condemned Damascus and threatenedit with sanctions and French U.N. Ambassador Gerard Araud toldreporters on Monday that reaching a Security Council consensusto refer Syria to the ICC would be difficult.

"As France is concerned it's very clear we are very much infavor of referring Syria to the ICC," Araud said.

"The problem is it will have to be part ... of a globalunderstanding of the council and I do think that for the momentwe have not yet reached this point," he said.

U.N. human rights chief Navi Pillay on Monday reiterated herposition that the issue of Syria's conflict should be referredto the ICC in The Hague because crimes against humanity andother war crimes may have been committed.

She said both sides appear to have committed war crimes.

The United Nations has said more than 10,000 people havebeen killed during the 16-month Syria conflict.

The complete Human Rights Watch report, which includes mapsof the detention centers, can be seen here: http://www.hrw.org/reports/2012/07/03/torture-archipelago-0